JP6092881B2 - Filtration unit - Google Patents

Description

  The present invention relates generally to fluid filtration, and more particularly to filtration of motor vehicle fluids including the filtration of air taken up by an internal combustion engine.

  As is well known, the air (or gas in general) entrained by an internal combustion engine is typically from air so that suspended solid particles, typically various types of powder, do not reach the engine combustion chamber. A filtration process is applied which is intended to remove and purify the solid particles. This stage of filtration is typically performed by a special filtration unit located along the intake line of the internal combustion engine, upstream of the intake manifold and, if present, the turbocharger.

  The filtration unit is generally referred to as a filtration box and is generally enclosed in the filtration box with an outer casing provided with an inlet for filtered air and an outlet for filtered air. And a filtration cartridge for filtering the air flowing toward the outlet. The filtration cartridge comprises at least one filtration material element, for example based on cellulose or polymer material, and at least one support plate for the filtration material element. The support plate is coupled to the filtration box such that the filtration material element divides the internal volume of the filtration box into two separate chambers with a first chamber in communication with the inlet and a second chamber in communication with the outlet. Is done. In this way, air flowing from the inlet to the outlet of the filtration box is directed across the filtration material element, which retains suspended solid particles. Assuming that the solid particles gradually plug the filter material element, it is usually possible to remove the filter cartridge from the filter box in order to replace the filter cartridge when the filter material element becomes excessively clogged. .

  One of the main needs for this type of filtration unit is to maintain a high filtration capacity over time, i.e. a filter cartridge that can guarantee a high useful life and thus reduce the number of interventions for its replacement. Is to provide.

  A filtration unit having a filtration membrane combined with a centrifuge system for separating the coarsest solid particles disposed in a first chamber in communication with the inlet of the filtration unit is intended to meet this need. Has been proposed.

  U.S. Pat. No. 6,057,051 discloses, for example, an air filter whose outer casing defines an internal environment, in which the first chamber communicates with an inlet for air to be filtered. A substantially toroidal filtration membrane, which is positioned to divide into a second chamber connected to the outlet of the filtered air, is inserted. The upper wall of the casing is formed with a hole provided with a fin of the deflector, and such hole defines an air inlet. The fins in particular impart a spiral motion to the air in the casing.

  Furthermore, the inner wall of the casing has one or more propellers that extend throughout the longitudinal extension of the casing to enhance the windmill motion imparted to the air in the first chamber of the casing. .

  The windmill motion imparted by the fins and by the propellers ensures that the heaviest fraction of solid impurities from the air entering the first chamber is pre-separated before traversing the filtration membrane. And prevent such particles from clogging the filtration membrane too quickly. Next, a hole having a fan is provided in the vicinity of the bottom of the casing for discharging solid impurities separated in the chamber upstream of the filtration membrane due to the centrifugal action imparted to the air.

  Although this technical solution extends the life of the filtration cartridge, the dimensions of the filtration membrane (outer diameter, inner diameter, height) are used to accommodate large amounts of solid impurities that accumulate on the propeller when used at high air flow rates. ), And a significant increase in the dimensions of the first chamber and the height of the propeller, i.e. all this is due to the large overall dimensions of the filtration unit and the solids of impurities present in the air to be filtered. It exposes the disadvantage of the fact that it leads to a reduction in the efficiency of separating the fractions in advance.

  Furthermore, a further drawback with filtration units using known types of centrifugal prefiltration action is that the casing shape and dimensions are limited by the desired centrifugal effect, so that the outer casing is always substantially cylindrical and large. In the unlikely event that there is a need to filter the air flow rate, the outer casing will have a substantial overall dimension.

  This therefore requires that the casing of the filtration unit must have a complex configuration due to the need for overall dimensions in the vehicle's engine compartment or be small in size. This suggests that this type of filtration unit is rarely used in automotive industry applications.

U.S. Pat. No. 4,303,423

The object of the present invention is to overcome the above-mentioned drawbacks of the prior art by simple, rational and inexpensive means.
These objects are achieved by the features of the invention as described in the independent claims. The dependent claims outline preferred and / or particularly advantageous embodiments of the invention.

  Specifically, the present invention includes at least one filtration membrane and is housed in an outer casing provided with the inlet and the outlet so as to filter a fluid flowing from the inlet toward the outlet, and the filtration membrane. Provides a filtration cartridge comprising at least one tubular body secured to be at least partially wound, the tubular body comprising at least one fin extending spirally from an inner wall of the tubular body .

  By this means, the filtration capacity of the filtration cartridge becomes independent of the size and shape of the casing of the filtration unit into which the filtration cartridge is inserted.

Furthermore, one aspect of the present invention provides that the fin is provided with a height that is substantially equal to the difference between the inner diameter of the cylindrical body and the outer diameter of the filtration membrane.
Thus, the fin height can be dimensioned to optimize the collection of solid particulates as a function of air flow across the filtration cartridge.

One aspect of the present invention provides that a variable pitch is provided in the fin along the longitudinal axis of the cylindrical body.
This means allows the air path and velocity to be optimized before the air crosses the filtration membrane, thereby facilitating the separation of the coarse solid portion from the air to be filtered.

Yet another aspect of the present invention provides that the filtration membrane is provided with a closed end and an open opposing end.
Advantageously, the tubular body comprises at least one annular abutment fixed to the open end of the filtration membrane so as to separate the environment in the filtration membrane from the external environment.
This measure makes it possible to efficiently centrifuge coarse solid particulates and to provide a forced passage for air that ensures efficient filtration through the filter membrane.

A further aspect of the invention provides that the tubular element comprises at least one discharge gap on its side wall.
This means makes it possible to discharge the separated solid fine particles to the outside of the cylindrical body due to the centrifugal action from the fins of the cylindrical body.

  Further, according to one aspect of the present invention, the filtration cartridge includes a plurality of filtration membranes and a plurality of cylindrical bodies, and each of the filtration membrane and the cylindrical body is formed on the support element. It is provided that the hole is associated with the support element.

  By this means, a filtration cartridge with several filtration membranes arranged so that the flowing air crosses in parallel uses the same filtration material. Significantly increases the filtration surface on which suspended solid particles can be deposited, thus further extending the life of the filter cartridge species.

  Furthermore, the overall dimensions of the filtration cartridge may, on the contrary, be limited regardless of the use of many air streams to be filtered.

A further aspect of the invention is housed in the casing to filter the fluid flowing from the inlet (11) towards the outlet (12), with an outer casing provided with at least one inlet and outlet. A filtration unit comprising the above filtration cartridge is provided.
The filtration membrane divides the inner volume of the casing into a first volume communicating with the inlet and a second volume communicating with the outlet.

  Further features and advantages of the present invention will become apparent from the following description, given by way of non-limiting example, with reference to the figures illustrated in the accompanying drawings.

FIG. 7 is a cross-sectional view taken along the line II of FIG. 6 for a filtration unit according to an embodiment of the present invention. FIG. 3 is an axial projection view of a filtration cartridge according to an embodiment of the present invention. It is a side view from III of FIG. FIG. 4 is a view taken along section IV-IV in FIG. 3. It is a figure which shows the state without the filtration membrane of FIG. It is a side view of the filtration unit of FIG.

  FIG. 1 shows a filtration unit 1 that purifies the air stream by removing solid particles, possibly present in suspension. More specifically, the filtration unit 1 is intended to be positioned along the intake line of the internal combustion engine so as to filter the combustion sustaining air supplied into the combustion chamber of the engine.

  The filtration unit 1 comprises an outer casing 10, conventionally called a filtration box, which can be provided entirely formed of a plastic material. The outer casing 10 delimits the internal volume, and the outer casing 10 is provided with an inlet 11 for filtered air and an outlet 12 for filtered air, both of which are described above. Communicate with product. While the outlet 12 is typically maintained in communication with the engine combustion chamber via the intake manifold, the inlet 11 is intended to remain in communication with the external environment.

The outer casing 10 has a polyhedral shape as a whole. In this case, the outer casing 10 is a polyhedron that extends along the longitudinal axis A.
In this case, the outer casing 10 has a substantially drinking glass shape having a central axis substantially parallel to the longitudinal axis A at the bottom 130 (right side in FIG. 1) and a conduit 131 that forms the inlet 11. A first main body 13 is provided.

The upper portion of the first main body 13 includes a bent end portion 132 that forms a surface substantially orthogonal to the side wall of the first main body.
Further, the outer casing 10 similarly has a substantially drinking glass having a central axis substantially parallel to the longitudinal axis A at the bottom 140 (left side in FIG. 1) and a pipe line 141 that forms the outlet 12. A second main body 14 having a shape is provided.

  The upper portion of the second body 14 includes a bent end 142 that forms a surface that is substantially orthogonal to the sidewall of the first body.

  The end 142 of the second body 14 faces the end 132 of the first body 13 to substantially hermetically seal the outer casing 10. The outer casing 10 has a substantially quadrangular cross section (in this example, a square shape), but it cannot be excluded that the cross section may be formed in a different shape, and varies depending on the needs of assembly. The same applies to the arrangement of conduits 132 and 142 in each body that can be shaped into a shape.

  The filtration unit 1 is provided with a filtration cartridge, indicated generally at 2 and mounted in the casing 10.

As illustrated in FIGS. 2 to 4, the filtration cartridge 2 includes a substantially flat support flange 20 provided with a plurality of through holes 21 and 5 arranged so as to form a five-point shape in this case. I have.
The filtration cartridge 2 further includes a plurality of cylindrical bodies 30 that are substantially cylindrical.

  Each first end 31 of the cylindrical body 30 is attached to the support flange 20 coaxially with the through-hole at each through-hole. The support flange 20 having a shape that is paired with the cross section of the outer casing 10 in a plan view is provided between the end 132 of the first body 13 and the end 142 of the second body 14 through a suitable sealing gasket, for example. Thus, the cylindrical body 30 is accommodated inside the first main body 13, that is, facing the inlet 11.

  In the illustrated embodiment, each tubular body 30 is integrally secured to the support plate 20 by, for example, gluing or any other equivalent means, but the tubular body 30 is, for example, the art. It may not be excluded that it may be removably attached to the support plate 2 by means of a snap connection or a plug connection known to those skilled in the art.

  The first end portion 31 of each cylindrical body 30 has an annular contact portion 310 having an inner diameter that is smaller than the diameter of the cylindrical body and substantially equal to the diameter of the through-hole 21, For substantial sealing connection between the tubular body 30 and the support flange, it is intended to rest on the support flange 20 which substantially forms the contour of the through-hole 21.

  In the preferred embodiment shown, each tubular body 30 extends from a first end 31 to a second end 33 throughout the longitudinal extension of the tubular body 30, a helical extension. at least one fin 32 having a development), which originates from the inner wall of the tubular body 30.

However, it is not excluded that the fins 32 extend over a limited portion of the longitudinal extension of the tubular body 30, for example, over the proximal portion of the second end 33. The length of the portion where the fin 32 extends is, for example, the flow rate in question in the filtration unit 1, the cross-section of the available air passage and the desired performance (pressure drop caused by the fin 32, solids removed from the air by the fin). Depending on particle deposition etc.).
The fin 32 has a height (the distance from the top to the inner wall of the cylindrical body 30) equal to the difference between the inner diameter of the cylindrical body and the diameter of the through hole 21 at the maximum.

Further, the fins 32 have a variable pitch along the longitudinal axis of the cylindrical body 30. For example, the fins 32 are continuously directed from the second end portion 33 toward the first end portion 31. It has a decreasing pitch.
In addition, the cylindrical body 30 may be provided with helical fins 32 (the illustrated example starts from locations that are observable in FIG. 2 and spaced angularly from each other by 90 °. Having four fins 32) cannot be ruled out.

Further, each cylindrical body 30 is provided on the side wall of the cylindrical body 30 and includes at least one discharge gap 34 obtained at the first end portion 31.
In this example, the filtration cartridge 2 further includes a plurality of cylindrical filtration membranes 40 each having a closed end 41 by pressing the filtration membrane 40 through a shielding plate or the like, for example. And an open end 42 on the opposite side facing the support flange 2 in one of the through holes 21.

Actually, each filtration membrane 40 is coaxially fixed in the cylindrical body 30, so that the open end 42 is moved so as to contact the inner surface of the annular contact portion 310.
Actually, each of the filtration membranes 40 is completely fixed in the cylindrical body 30, so that the fins 32 are in contact with the outer side surface of the filtration membrane.

  In the illustrated first embodiment, each filtration membrane 40 is fixed, for example, by gluing the open end 42 to the abutment element 32. In a second alternative embodiment, each filtration membrane 40 is provided at its open end 42 with a sealing coupling means which is decoupled with a corresponding coupling means formed in the annular abutment 310, known in the sector. Provided with an annular plate.

  In the preferred embodiment shown, each tubular body 30 has a longitudinal extension that is substantially less than the longitudinal extension of each filtration membrane 40, so that the closed end 41 of the filtration membrane 40 is It protrudes to the outside with respect to the cylindrical body.

  However, the cylindrical body 30 may have a length that is longer than or equal to the length of each filtration membrane 40, and the cylindrical bodies 30 in addition to the filtration membrane 40 of the filtration cartridge 2 are mutually connected. It is not excluded that they may have different lengths and / or dimensions with respect to.

  Preferably, each filtration membrane 40 is obtained from a non-woven material formed of mutually twisted fibers, the non-woven material being made by a melt blow process and made of polymer type fibers, such as polypropylene. The filter membrane 40 may alternatively be formed from a nonwoven fabric using fibers made of cellulose and / or polymeric material and / or fiberglass. A pleated membrane type may also be used.

In light of the description outlined above, the filtration unit 10 operates as follows.
All of the air flowing from the inlet 11 to the outlet 12 of the casing 10 is directed to enter the axial direction in the gap formed between each filtration membrane 40 and each cylindrical body 30, where the fin 31 As a result, a windmill-like rotational motion is given.

  The solid particles suspended in the air are separated from the air due to the centrifugal force, collected by the fins 31, and conveyed toward the discharge gap 34, and from the discharge gap 34, for example, the first main body 13. Falls due to gravity on the lower wall of the.

  In this way, the air from which the coarsest solid particles have been previously separated is directed to pass through the filtration membrane 40 (crossing the filtration membrane 40 from the outside to the inside), thereby to the desired extent. The air is completely filtered, and the air passes from the first main body 13 through the second main body 14 via the through-hole 21 and finally exits from the outer casing 10 via the outlet 12.

Many improvements and modifications can be made to the invention thus conceived, all within the concept of the invention.
Moreover, all details can be replaced by other technically equivalent elements.
Indeed, in addition to the materials used, the swings and associated dimensions may be varied as needed without departing from the scope of protection of the following claims.

Claims (10)

An outer casing (10) provided with at least one inlet (11) and one outlet (12);
A filtration cartridge (2) comprising at least one filtration membrane (40) and housed in the outer casing ( 10 ) so as to filter fluid flowing from the inlet (11) toward the outlet (12); With
The filtration cartridge (2) comprises at least one tubular body (30) fixed so that the filtration membrane (40) is at least partially wound;
The tubular unit (30) includes at least one fin (32) spirally extending from the inner wall of the tubular body (30), and at least one discharge gap (34) on the side wall thereof. (1).   The filtration unit (1) according to claim 1, wherein the fin (32) has a height substantially equal to a difference between an inner diameter of the tubular body (30) and an outer diameter of the filtration membrane (40). The filtration unit (1) according to claim 1, wherein the fin (32) is provided by changing a pitch of the fin (32) along a longitudinal axis of the cylindrical body (30).   The filtration unit (1) according to claim 1, wherein the filtration membrane (40) has a closed end (41) and an opposite open end (42).   At least one annular contact portion that is fixed to the open end (42) of the filtration membrane (40) so that the cylindrical body (30) separates the environment in the filtration membrane (40) from the external environment. The filtration unit (1) according to claim 4, comprising (310).   The filtration unit (1) according to claim 5, wherein the annular contact portion (310) is provided at an end (31) of the cylindrical body (30).   The filtration unit (1) according to claim 1, further comprising a support element (20) provided with at least one through-hole (21) to which the cylindrical body (30) is attached coaxially.   The filtration unit (1) according to claim 7, wherein the cylindrical body (30) is fixed integrally to the support element (20).   The filtration unit (1) according to claim 7, wherein the tubular body (30) is detachably attached to the support element (20) by a coupling means. A plurality of filtration membranes, and a plurality of cylindrical bodies,
The filtration unit (1) according to claim 7 , wherein each of the filtration membrane and the cylindrical body is attached to the support element at a position of each hole formed in the support element.

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